<!DOCTYPE html>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<div id="host">
  <div style="overflow:scroll">
    <div contenteditable></div>
  </div>
</div>
<script>
  test(() => {
    const root = host.attachShadow({mode:"open"});
    root.innerHTML = `
      <div style="overflow:scroll">
        <div contenteditable></div>
        <slot></slot>
      </div>
    `;
  }, " Editing causing fallback to legacy layout for nested BFCs should not crash.");
</script>
